Supervisory system



Aug. 27, 1940 v. DURBIN 2,212,660

SUPERVISOR! SYSTEM Filed Feb. 24, 1938 AMPLIFIER AMPLIFIER I I Tm f L 76F/EQJ] 3 5 ,4 5R L LINE Witness 2 C fi l/enter 66 %f7M-n/ Patented Aug. 27, 1940 UNITED STATES PATENT OFFICE Holtzer-(Iabot Electric Company,

Roxbury Mass.; a corporation of Massachusetts Application February 24, 1938, Serial No. 192,238

8' Claims. (Cl. 179-1) The present invention relates to supervisory systems and more particularly to systems for detecting unusual conditions within a building.

The principal object of the present invention is to provide a system which may be used in place of, or in conjunction with, a watchmans report system for exercising constant supervision over all parts of the building to be protected. A further object of the invention is to provide means to be employed with a personal watch system, whereby communication between the central station and any of the watchmens stations may be established.

With these objects in view the principal feature of the present invention comprises a plurality of local transmitting stations placed at suitable points within the building to be protected, and arranged to be successively connected with a central station in accordance with a cyclic control whereby any noises originating in the neighborhood of any of the local stations would be transmitted to the central station. Another feature of the invention comprises means whereby the cyclic control may be interrupted and connection established with any selected local station for closer investigation.

Another feature of the invention comprises a modification of the foregoing, whereby the instruments used for supervision may be employed for communication between the local stations and the central station.

In the accompanying drawing Fig. 1 is a diagram of one form of system according to the present invention; and Fig. 2 is a diagram illustrating a modified system.

In the system shown in Fig. 1, a number of microphones designated M M and M constituting local stations, are placed at strategic positions in the building to be protected. The microphones are successively connected for brief intervals with an amplifier A located in the head watchmans oflice. To the output of the amplifier is connected a loudspeaker L.

The means by which the microphones are successively connected with the amplifier comprises a rotary selector switch 4 having a plurality of opposed pairs of fixed contacts 6 and 8 adapted to be swept by a pair of movable contacts Ill. The microphones M M and M are connected by paired conductors l2, l4 and "5, respectively to opposed fixed contacts 6 and 8 of the switch; for the particular instant illustrated in Fig. 1, the sweep contacts I are connected through the conductors IS with the microphone M The sweep contacts ll! of the switch are operated by a shaft l8 intermittently rotated by a pawl 20 and ratchet 22. The intermittent operation is preferably effected by a motor 24 driving a cam 26 through a suitable gear reduction, the cam acting once each revolution through con- 'tacts 28 to break the circuit of an electromagnet 30, having a pivoted armature 32 depending from the pawl. Upon subsequent closure of the circuit through advancement of the cam, the pawl is attracted to advance the ratchet one tooth. The pitch of the ratchet teeth corresponds to the spacing of the contacts 6 and 8. A suitable dial 34 with an indicating pointer may be used to indicate the particular station for which the contacts are at any time established. 16

The contacts ID are connected by a pair of wires 36 to contacts 38 and 40 o! a change-over switch C. The-connection of the sweep contacts In to the wires 36 is preferably by the use of slip rings as diagrammatically illustrated. in the drawing. The blade contacts and 44 01 the change-over switch are connected by conductors 46 to the input of the amplifier.

The change-over switch is provided with an additional contact 48 engaged by a blade 50 when the contacts 42 and 44 are closed on the contacts and 40. The contacts 48 and 50 control the circuit for the motor and the electromagnet 30. From one side of the supply line a lead 52 runs to the motor and connects with a wire 54 leading to the electromagnet, whfle the other side of the line connects the blade 50 of the switch, the contact 48 being connected by a wire 56 with the other side oi. the motor, and through a wire 58 with the cam-controlled contacts 28. Upon closure of the change-over switch to its right-hand position, the motor and electromagnet are therefore operated to advance the selector switch intermittently, and the microphones are connected successively in the circuit with the amplifier. The time during which the separate microphones are connected with the amplifier is preferably from six to ten seconds. For a sixsecond connection the selector switch is able to connect twenty microphones with the amplifier 4 in a two-minute cycle.

The amplifier is energized by a connection 59 to the line ahead of the switch 0.

The head watchman, upon hearing any suspicious noises at the loudspeaker, may throw out the selector mechanism and cut in the microphone corresponding to the station from which such noises are received, for the purpose of enabling a closer investigation to be made. For this purpose a series or manual switches is provided, one for each of the microphones. These switches are shown diagrammatically as doublepole single-throw switches S S" and S Taking the switch S for example, the movable contacts thereof are connected by paired leads to the circuit conductors l2 of the microphone M Similarly the movable contacts of the manual switches S and S are connected by leads 62 and 64 with the circuits l4 and I6, respectively.

Corresponding fixed contacts of the several switches are connected by wiring indicated generally at 66, to contacts 68 and 10 of the change-over switch C. The contacts 88 and Ill are opposite the contacts 38 and 40 and are adapted to be engaged by the blade contacts 42 and 44 thereof when the change-over switch is thrown to its left-hand position. To supervise any particular station therefore, the operator simply throws the change-over switch to its lefthand position, thereby disconnecting the amplifier input from the automatic switch circuit and connecting it with the manual circuit 66. The opening of contacts 48, 50 also breaks the motor circuit and prevents further advance of the selector switch. Any one of the manual switches B may then be closed to connect the corresponding microphone to the amplifier. When it is desired to resume automatic operation, the changeover switch is thrown to its right-hand position, whereupon the selector switch resumes the cycle at the point at which it was interrupted.

For the system shown in Fig. 1 wherein communication is in one direction only from the local stations to the central loudspeaker, the microphones may be of any desired type. It has been found, however, that the common magnetic type loudspeaker serves as an excellent microphone for the purposes described. Moreover, it has the advantage of permitting communication in both directions between the outlying stations and the central station, according to another fea ture of thepresent invention, involving the modified system shown in Fig. 2.

Only the change-over switch C, the conductors 36 leading from the rotary selector switch, and the conductors 66 forming the manual circuit are repeated in Fig. 2. The conductors 45 from the change-over switch, instead of leading to the amplifier, are connected through conductors l2 and 74 with contacts i6 and 18 respectively, at opposite sides of a four-pole double-throw switch P of which the upper pair of movable contacts 88 is connected by conductors 82 to the amplifier input, and the lower pair of movable contacts by conductors 84 to the amplifier output. A telephone transmitter T is connected by. conductors 86 to contacts 88 opposite the contacts F6. The contacts 90 opposite the contacts 78 are connected to a receiving circuit 92 provided with a doublethrow switch for connection to either the loudspeaker L or a telephone receiver R.

When the switches C, P and 94 are in their right-hand positions, the connections from the rotary selector lead to the amplifier input through conductors 46, I2 and 82, and the amplifier output is fed to the loudspeaker through conductors 84 and 92. This gives the normal cyclic operation as described in connection with Fig. 1. When the switch C is thrown to its left position, the switches P and 94 remaining unchanged, a selected microphone may be manually connected to operate the loudspeaker for an investigation of unusual noises, as also described for the system of Fig. 1.

To permit communication from the central station to a desired outlying station the switch C must be in the left-hand position, and the manual selector switch S corresponding to the particular station must be closed. Furthermore, the switch P must be thrown to the left, thereby con necting the transmitter T with the amplifier input and connecting the lines 84, 86 with the amplifier with the selected station through 84, 74, 46, the manual control circuit 66 and the selected manual switch S. If a reply is then to be received from the outlying station, the switch P is thrown to the right, thereby connecting the microphone of the outlying station with the input of the amplifier, and connecting the output of the amplifier with the receiving circuit 92. Under these latter circumstances, it may be desirable to receive the message on the receiver R rather than on the loudspeaker L, and for this purpose the switch 94 is thrown to the left.

It will be understood that Fig. 2 is diagrammatic only and that for simplified operation any usual transmitting and receiving equipment may be employed. For example, the transmitter T and receiver R are preferably combined in a hand set, the switch 94 being automatically operated when the hand set is removed from the hook.

It may also be desirable to throw the switch C- automatically to the left at this time, and for that purpose any suitable relay arrangement may be used. The switch P is a talk-listen switch which is manually operated at the central station.

In protection of large buildings, a watchmans report system is frequently used, operating on the principle of compelling each watchman, in accordance with a regular schedule, to transmit signals to the central station from the local stations on his round. Usually the system makes use of anannunciator by which the positions of the watchmen are indicated at the scheduled times. Since the present invention, in the form shown in Fig. 1, provides substantially complete supervision of the whole building, it may be used in place of a personal watch system. Its greatest value, however, particularly in the modification of Fig. 2, is in its use in conjunction with a personal watch system, whereby a more complete protective coverage is obtained. The report system, if used, may be of any well-known type, and is not herein described.

To summarize, the present invention affords an opportunity for extensive supervision of a building, first, by providing a cyclically operated detection system whereby any unusual noises originating in substantially any part of the building may be transmitted to the central station; second, in providing means whereby the cyclic control may be disabled, and any associated station may be connected with the central station for closer investigation of unusual conditions; and, third, in the arrangement of Fig. 2 the use of means whereby the same apparatus may be employed to afiord communication in both directions between the central station and any outlying station.

Having thus described the invention, 1 claim:

1. A supervisory system comprising a plurality of microphones adapted to be placed at points of a building to be supervised, a loudspeaker, means for successively connecting the microphones with the loudspeaker in a definite rapid cycle, and means for disabling the cyclic connection and for permitting manual connection of a selected microphone with the loudspeaker.

. 2. A supervisory system comprising a plurality of microphones adapted to be placed at points of a building to be supervised, a loudspeaker, cyclic control means for successively connecting the microphones with the loudspeaker in a definite rapid cycle, manual control means for connecting a selected microphone with the loudspeaker, and change-over means for the cyclic and manual controls.

3. A supervisory system comprising a plurality of local transmitting and receiving stations, a central station, cyclic control means for successively connecting the local stations for transmission therefrom to the central station in a definite rapid cycle, means operated at the central station for disabling the cyclic control, and means for establishing communication in either direction between the central station and a selected local station.

4. A supervisory system comprising a plurality of local stations, each including a transmitting and receiving device, a central station having an amplifier, cyclic control means for successively connecting the local stations with the amplifier input in a definite rapid cycle, manual control means for disabling the cyclic control and for connecting a selected local station with the central station, and talk-listen means operating to connect the selected local station with either the input or the output of the amplifier.

5. A supervisory system comprising a plurality of local stations each comprising a transmitter unit, a central station having a speaker unit, automatic cyclic control means for successively connecting the local stations with the amplifier to transmit sounds from the vicinity of the several local stations to the central station, and manually controlled means for disabling the cyclic control and for connecting any selected local station with the central station.

6. A supervisory system comprising a plurality of local stations each comprising a transmitter unit, a central station having a speaker unit, automatic cyclic control means for successively connecting the local stations with the amplifier to transmit sounds from the vicinity of the several local stations to the central station, a set ofseleotor switches for manually connecting any selected local station with the central station, and change-over means for shifting control from the cyclic control means to the selector switches.

'7. A supervisory system comprising a plurality of local stations each comprising a transmitter unit, a central station having a speaker unit, automatic cyclic control means for successively connecting the local stations with the amplifier to transmit sounds from the vicinity of the several local stations to the central station, a set of selector switches for manually connecting any selected local station with the central station, and change-over means for simultaneously disabling the cyclic control means and shifting control to the selector switches.

8. A supervisory system comprising a plurality of local stations each having a unit capable of operating as a transmitter or receiver, a central station having a speaker unit, automatic cyclic control means for successively connecting the local stations with the amplifier to. transmit sounds from the vicinity of the several local stations to the central station, a set of selector switches for manually connecting any selected local station with the central station, changeover means for shifting control from the cyclic control means to the selector switches, and talklisten means operable when the control is by an individual selector switch for permitting transmission in either direction between a local station and the central station.

VERNON DURBIN. 

